Processability theory, question constructions and vocabulary learning in English L2

The paper introduces Procesability Theory(PT) and a second language acquisition (SLA henceforth) cross-sectional investigation. It illustrates how PT may be used in studying the relationship between question constructions (both yes/no-and wh-questions) and vocabulary learning in English as a second language (ESL). The study involves nine adult Japanese Ll-English L2 late bilinguals in Australia, selected out of a total of 22 who sat for a standardised vocabulary size test, three each from Top, Middle and Low vocabulary size groups. These nine informants performed, additionally, communicative oral production tasks for second language (L2) speech profiling. The linguistic production of each informant was analysed against PT syntactic schedule for English L2 question constructions. Results suggest that vocabulary and syntactic development are closely related. Low and Mid vocabulary site ESL learners have problems in specific areas of question constructions, such as the choice of auxiliary verbs. High vocabulary learners, on the other hand, were able to cope with the whole range of question constructions investigated in the study. Question constructions were confirmed to be a key indicator of ESL learners' syntactic development.